/***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2007 Ola Bini <ola@ologix.com>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby;

import org.jruby.anno.JRubyClass;
import org.jruby.exceptions.CatchThrow;
import org.jruby.runtime.Block;
import org.jruby.runtime.ClassIndex;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;

import static org.jruby.api.Create.newString;
import static org.jruby.api.Define.defineClass;

/**
 * Minimal RubyContinuation class to support third-party users.
 */
@JRubyClass(name="Continuation")
@Deprecated(since = "9.2.6.0")
public class RubyContinuation extends RubyObject {
    @Deprecated(since = "9.2.6.0")
    public static class Continuation extends CatchThrow {
        public Continuation() {
            super();
        }

        public Continuation(IRubyObject tag) {
            super(tag);
        }
    }

    private final Continuation continuation;
    private boolean disabled;
    
    public static RubyClass createContinuation(ThreadContext context, RubyClass objectClass) {
        return defineClass(context, "Continuation", objectClass, objectClass.getAllocator()).
                reifiedClass(RubyContinuation.class).
                classIndex(ClassIndex.CONTINUATION).
                tap(c -> c.singletonClass(context).undefMethods(context, "new"));
    }

    @Deprecated(since = "9.2.6.0")
    public RubyContinuation(Ruby runtime) {
        super(runtime, runtime.getContinuation());
        this.continuation = new Continuation();
    }

    /**
     * A RubyContinuation used for catch/throw, which have a tag associated
     *
     * @param runtime Current JRuby runtime
     * @param tag The tag to use
     */
    @Deprecated(since = "9.2.6.0")
    public RubyContinuation(Ruby runtime, IRubyObject tag) {
        super(runtime, runtime.getContinuation());
        this.continuation = new Continuation(tag);
    }

    @Deprecated(since = "9.2.6.0")
    public Continuation getContinuation() {
        return continuation;
    }

    @Deprecated(since = "9.2.6.0")
    public IRubyObject call(ThreadContext context, IRubyObject[] args) {
        if (disabled) {
            RubyKernel.raise(context, context.runtime.getThreadError(),
                    new IRubyObject[]{newString(context, "continuations can not be called from outside their scope")},
                    Block.NULL_BLOCK);
        }
        continuation.args = args;
        throw continuation;
    }

    @Deprecated(since = "9.2.6.0")
    public IRubyObject enter(ThreadContext context, IRubyObject yielded, Block block) {
        try {
            return block.yield(context, yielded);
        } catch (Continuation c) {
            if (c == continuation) {
                if (continuation.args.length == 0) {
                    return context.nil;
                } else if (continuation.args.length == 1) {
                    return continuation.args[0];
                } else {
                    return RubyArray.newArrayMayCopy(context.runtime, continuation.args);
                }
            } else {
                throw c;
            }
        } finally {
            disabled = true;
        }
    }
}// RubyContinuation
